From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: [PATCH v2] pci: fix unavailable irq number 255 reported by BIOS Date: Tue, 26 Jan 2016 10:51:56 +0100 (CET) Message-ID: References: <1453705178-27389-1-git-send-email-chen.fan.fnst@cn.fujitsu.com> <20160125205803.GA10272@localhost> <56A7404A.8080205@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Return-path: Received: from www.linutronix.de ([62.245.132.108]:33993 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964956AbcAZJxH (ORCPT ); Tue, 26 Jan 2016 04:53:07 -0500 In-Reply-To: <56A7404A.8080205@cn.fujitsu.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Chen Fan Cc: Bjorn Helgaas , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, rjw@rjwysocki.net, lenb@kernel.org, izumi.taku@jp.fujitsu.com, wency@cn.fujitsu.com, caoj.fnst@cn.fujitsu.com, ddaney.cavm@gmail.com, okaya@codeaurora.org, bhelgaas@google.com, jiang.liu@linux.intel.com, linux-pci@vger.kernel.org On Tue, 26 Jan 2016, Chen Fan wrote: > On 01/26/2016 04:26 PM, Thomas Gleixner wrote: > > > > if (gsi < 0) { > > > > - if (acpi_isa_register_gsi(dev)) > > > > +#ifdef CONFIG_X86 > > > > + /* > > > > + * The Interrupt Line value of 0xff is defined to mean > > > > "unknown" > > > > + * or "no connection" (PCI 3.0, Section 6.2.4, footnote on > > > > page > > > > + * 223), using ~0U as invalid IRQ. > > > > + */ > > And why would this be x86 specific? PCI3.0 is architecture independent, > > right? > quoting the spec document: > "For x86 based PCs, the values in this register correspond to IRQ numbers > (0-15) of the standard dual > 8259 configuration. The value 255 is defined as meaning "unknown" or "no > connection" to the interrupt > controller. Values between 15 and 254 are reserved." So if that is x86 specific then it needs to be documented proper. The fact that the comment is inside the #ifdef x86 does not tell. Thanks, tglx